The primary focus of this project has shifted somewhat from the application and improvement of various psychophysical procedures to the evaluation of the relative merits of different methods for studying color vision. Rod and cone threshold measurements are still made on many patients, particularly on those having or suspected of having toxic or degenerative retinopathies. Many of these patients have been found to have some degree of deficiency in their perception of certain colors, and because this determination can be made by some of the newer methods, it seemed imperative to study any existing correlations. Tests were conducted on 145 patients during the past year, including those on or beginning therapy for macular degeneration, systemic lupus erythematosus, rheumatoid arthritis, diabetes mellitus, and sickle cell anemia.